P17.19.B Incidence of treatment-associated imaging changes in newly diagnosed MGMT promoter-methylated glioblastoma treated with cilengitide (EORTC 26071 - CENTRIC study): interim analysis. (5th September 2022)

• Record Type: Journal Article
• Authors: Flies, C M; Friedrich, M; Lohmann, P; van Garderen, K; Smits, M; Tonn, J C; Weller, M; Galldiks, N; Snijders, T J
• Is Part Of: Neuro-oncology. Volume 24(2022)Supplement 2
• Page Start: ii93
• Page End: ii93
• Publication Date: 2022-09-05
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noac174.327
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: Background: In patients with glioblastoma, radiological recurrence of enhancing tissue after chemoradiotherapy can originate from progressive disease (PD) or from pseudoprogression/treatment-associated changes. There are no widely approved consensus criteria for treatment-associated changes. In the randomised EORTC-CENTRIC study (NCT00689221), patients with MGMT promoter-methylated glioblastoma were treated with chemoradiotherapy or chemoradiotherapy with cilengitide, an integrin inhibitor. We assessed the rate of treatment-associated changes in these groups according to the modified response assessment in neuro-oncology (RANO) criteria of 2017. Methods: CENTRIC patients from both study arms with ≥3 follow-up MRIs were included. Preliminary PD (PPD) was defined as a ≥25% increase of the sum of perpendicular diameter (SPD) of a new or increasing lesion compared to baseline or nadir on the T1-MRI with gadolinium. Subsequent PD was defined as a second ≥25% increase of the SPD, at least 4 weeks later, or as a new lesion outside the radiation field. Treatment-associated changes were defined as stabilisation on ≥2 follow-up MRIs after PPD, each one 4 weeks later, or partial/complete regression on ≥1 follow-up MRI 4 weeks later. Results: In total, 4, 051 MRIs from 584 patients were available. This interim analysis included data on 462 patients with similar proportions in the cilengitide and control arm (50.9% and 49.1%). Due to missing MRIs or values, 128 were excluded. Of the remaining 334 patients, 157 (47%) patients showed RANO measurable disease at baseline or nadir (median SPD, 0mm 2 ; interquartile range (IQR) 552.1 (0-552.1). After chemoradiotherapy with or without cilengitide, PPD occurred in 214 patients (64.1%) after a median time of 6.08 months after finishing radiation (IQR 11.4 (2.4-13.8), and 3.65 months after baseline or nadir (IQR 6.4 (2.1-8.5). After follow-up of these 214 patients, treatment-associated changes were diagnosed in 62 (18.6%) and PD was diagnosed in 48 (14.4%). The remaining 104 (31.1%) patients had no further follow-up MRI after PPD, mostly because a clinical decision to call PD was made. In the cilengitide group of 178 patients, 37 (20.8%) patients developed treatment-associated changes, and 23 (12.9%) patients developed PD, whereas in the control group of 156 patients, 25 (16%) patients developed treatment-associated changes, and 25 (16%) patients PD. Conclusion: With the modified RANO criteria, the rate of treatment-associated changes was low compared to previous studies in newly diagnosed MGMT promoter-methylated glioblastoma. This rate did not change with addition of cilengitide. RANO-recommended radiological follow-up was not always awaited, which reflects clinical practice. Full data will be presented.